1. Field of the Invention
This invention relates to an improved method for making amidoximes. The method uses an aqueous hydroxylamine solution and a nitrile at ambient temperature.
2. Brief Description of the Prior Art
Amidoximes of general formula R--C(NH.sub.2).dbd.NOH, where R is an alkyl or an alkoxy group, are used extensively as intermediates in manufacturing of other products. They are used in the pharmaceutical industry for preparation of a variety of different drugs, in optical brightners for textile materials and synthetic polymers, and in antibacterial and antiparasitic materials (see U.S. Pat. Nos. 3,991,067; 4,142,044; 4,122,257; and 4,144,391).
U.S. Pat. No. 3,897,447 discloses the application of amidoximes in synthesis of anthelmintic agents. The method disclosed for synthesis of acetamidoxime uses hydroxylamine hydrochloride, acetonitrile and potassium carbonate as starting raw materials in a multi-step process. Using raw material of this kind makes the process complicated and difficult. This reaction mixture also requires refluxing the mixture for 16 hours making the reaction process slow, costly and time consuming. In addition, since the starting material contains inorganic anionsand cations, the possibility of having ionic contamination is very high, thus making the final product impure. These processes normally give a low production yield due to the multiple steps required. Other amidoximes known in previous art are also prepared using similar methods starting with a corresponding nitrile compound in an alkaline media.